add a new Attestation token, for proving claims or DID ownership

[MichaelMure]

Specification is TBD

[alanshaw]

@MichaelMure I'm curious about this - I think we need something similar. What is the idea here? How does it work?

[MichaelMure]

@alanshaw we had a chat with @expede about the self-invocation thing and how/why use it, and it we figured that the semantic was odd at best. For this reason and other that she would explain way better, she thought that a new token type taylored for attestation (Alice claims X/Y/Z) would be better. There is no specification yet, it's just the result of a late night chat. It was just easy to piece together from the other part of the codebase.

It's more or less that self-invocation, but without fields that stop making sense, no subject (unclear if aud makes sense), and instead a set of arbitrary claims.

In my case, I'm looking into using this to bootstrap a relationship (aka "signup") between a client and a service.